Ultrasonic range finding

How It Works

This sensor finds objects with sound the same way a bat or dolphin does. One part of the sensor is a speaker that sends out a sound wave. The other part is a microphone that then measures how long it takes for the sound wave to come back. The longer it takes to come back, the further away the object:

Measure the time it takes for the sound to come back, and you can tell the distance. The speaker sends out the sound in a cone, so only objects within the cone will return sound and be detected. Objects in the center of the cone do best.

This sensor is a simple ultrasonic rangefinder. It cannot detect individual objects. It can only tell you how long it took the sound sent out to return. It will measure the closest object.

If the object absorbs sound, or if there is nothing for a long distance, or if the object bounces the sound at an angle, there might not be enough sound returning to measure anything.